1. Field of the Invention.
This invention relates generally to the manufacture of automotive interior members and vehicle seats, and more particularly to a method of attaching a seat cover to a seat cushion and to the laminated composites made thereby.
2. Description of the Prior Art
Presently, the manufacture of automotive interior members or vehicle seat covers and seats is a time consuming, labor intensive and expensive operation. In a typical method of manufacture, first a die-cut seat cover material 4 made of fabric or leather is matched and tack sewn to a corresponding die-cut low density polyurethane foam 6 by threads 8 to form a composite as shown in FIG. 1. In the case of seat covers, the tack sewn die-cut parts are then sewn together to form an entire seat cover. Finally, the seat cover is attached to a seat cushion either by mechanical fastening or adhesive bonding, such as the Sur-Bond.RTM. method or methods described in U.S. Pat. Nos. 4,874,488; 4,799,988; 4,737,266; 4,722,760 and 4,692,199. Generally, bench-type automobile seat covers are mechanically fastened to the seat cushions and bucket-type seat covers are adhesively bonded to the seat cushions.
The adhesive bonding methods described in the cited patents require either that a liquid adhesive be applied to the sew pad or that a weld sheet be sandwiched between the sew pad and the fabric. Heat is then applied to the seat cover to activate the adhesive and bond the sew pad to the cushion cover. When liquid adhesive is used, it must be applied to the sew pad at the seat fabrication site. This is cumbersome and time consuming. Often the liquid adhesive is not applied uniformly to the sew pad and this can result in an inferior bond between the sew pad and the cushion. The liquid adhesive also creates an environmental problem for seat fabricators due to the presence of solvents and other chemicals in the adhesive. Weld sheets are difficult to hold in place and to properly position. Additionally, all conventional bonding methods require the application of heat and/or steam to the seat cover to activate the adhesives. At times the heat can damage the cover material, especially leather, resulting in a high seat rejection rate.
Further, the rejection rate is high, not only due to heat damage to the seat cover during the bonding process and inferior bonding of the sew pad to the cushion, but also because of other factors, such as mismatched sew pads and cover material, improperly sewn seat covers, improperly die-cut seat cover material and/or sew pads and damage to the cover material from liquid adhesive material spilled thereon. Thus, seat cover manufacturers and automobile seat manufacturers must carry additional inventory to cover rejections and this results in additional manufacturing costs.
Therefore, it is an object of the present invention to limit the required inventory a seat fabricator must carry so that the fabricator need not stock both sew pad and seat cover material to be matched together. It is a further object of the invention to decrease the labor required to fabricate automotive seats. It is a further object of the invention to eliminate waste due to improper tack sewing. It is a further object of the invention to manufacture a seat cover which is the same as present seat covers but at a lower cost. It is yet a further object of the invention to eliminate the need to spray liquid adhesives onto the sew pad at the fabrication site. It is a further object of the invention to ensure that a uniform bond occurs between the sew pad and the seat cushion. And it is yet a further object of the present invention to eliminate the need for pollution control equipment at the manufacturing site of a seat cushion.